https://doi.org/10.1351/goldbook.M03949
Portion of matter consisting of two or more chemical substances called @C01281@.
Source:
Physical Chemistry Division, unpublished [Terms]
See also:
PAC, 1994, 66, 533. (Standard quantities in chemical thermodynamics. Fugacities, activities and equilibrium constants for pure and mixed phases (IUPAC Recommendations 1994)) on page 535 [Terms] [Paper]